Hello,
I'm using the function ICC1.CI of the psychometric package. I wonder if
there is an error in this function. Because in the paper of McGraw and
Wong (Psychol Met, 1, 30) or the one of Shrout & Fleiss (Psychol Bult,
86, 420), the Ftab is not calculate in the same manner of the lower and
upper bound.
According to these articles Ftab for the lower bound is:
F(df.row, df.error)
and for the upper bound, it is:
F(df.error, df.row).
So the df are reversed. However, in your function ICC1.CI, the Ftab is
calculated in the same way for the upper and lower bound:
Ftab <- qf(noma/2, df1, df2, lower.tail = F)
Fl <- Fobs/Ftab
Fu <- Fobs * Ftab
lcl <- (Fl - 1)/(Fl + n)
ucl <- (Fu - 1)/(Fu + n)
Is that an error ?
Best regards,
--
Mathieu d'Acremont, PhD Mathieu.Dacremont at pse.unige.ch
Ma?tre-Assistant tel/fax +4122 379 98 20/44
P?le de Recherche National en Sciences Affectives
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http://affect.unige.ch/